Food mixer control mechanism



W.` VAN GUILDE'R May Al5, 1951 FOOD MIXER CONTROL MECHANISM Filed Feb. 3, 1950 WALTER VANGUILDE 5) AgV/C'Varranwfy May 1.5, 1951 w. VAN GUILDER Foon MIXER CONTROL MECHANISM Filed Feb. s, 195o 3 Sheets-Sheet. 2

, Q QT May `15, 1951 w. VAN GUILDER FOOD MIXER CONTROL MECHANI'SM 3 sheets-sheet s Filed Feb. s, 1950 `'BY affanni-Aer,`

Patented May l5, 1,951

FOOD MIXERy CONTROIIMECHANISM Walter Van- Guilder, River .'Forest, .Ill.,..assignor to lGeneral Mills,.Inc., a corporationof 4Dela- Ware Application February 3, 1950, Serial'No. 142,271'

8 Claims. 1

The present applicationrelates to food mixers,

and more particularly to an improved control.

mechanism for a household food mixer.

Household food mixers are known in which aA casing is mounted above a -base for movement between operating and retracted positions. Such'a .casing carries a beater shaft at one end so that a beater mounted on the shaft can be moved into and out of operative position with respect tothe usual mixing bowl in response to movement of the casing between such positions. In some prior constructionsian automatic switch has been provided which deenergizes the electric motor or power source of the mixer in re-A sponse to movement-of the casing to its retracted position. In these cases the motor is then automatically re-energized when the casing is returned to operative position.

In most mixers, however, the 4particular position of the casing does not influence the energization of the motor so that it is possible to turn.

the mixer on or off,.even when the casing is retracted and the beater blades are in a position where they might readily be encountered by the Y will be apparent from the following specifica-v tion in which a preferred embodiment isdescribed with particular reference to the vaccompanying drawings.

In these drawings, in which like :reference v characters indicate. like parts,..

Figure 1 is a partial side view, with` certain portions shown in section and other portions broken away, of a household food mixer yemibodying features of the present invention;

Fig. 2 is a partial top view of part ofthe mech-.- anism of Fig. l, with the4 top covel` broken away for clearness;

Fig. 3 is a schematic perspective viewshowing further details of the device of Fig. 1; and

Fig. 4 is a partialside view,v with portionsin section and other portions broken aWay,. show#-v ing the device of Fig. l withfthe mixer casing .inV

retracted position.

Asshownvin Fig. l, the mixer includes a sta-1 v tionary `base portion I2, provided with means (not shown) for supporting the usual mixing bowl IIL A movable casing I4 is pivoted at I6 to the 4'base or pedestalportion I2, so that the casing I4 is movable `by rotation on axis I6 between` the operating position of Fig. 1 and the retracted knowntypes of mixer, asv long as the mixer inchiclesY a movable casing which can be tilted or otherwise shifted V between voperative and retractive positionswithrespect to a mixing bowl.

Almotor I8 is mounted in the movable casing.`

I4 in any desired Vfashion and serves as the power source. for the food. mixer. Casing I4 includes a portion Z which extends laterally above thel mixing Vbowl IG to support a beater drive shaft andobeater element in operative position Within thexbowl. Whilev any` desired form of beater construction may be used, I have shown a planetary headt rotatably mounted at the outer end of casing extension 23.1 Planetary head 22 includes a planetary shaft and attaching means 24 forv driving engagement with a shaft' 23 of a planetary. beater element 28..' The usual planetary gearing is provided so that on rotation of the head` 22 inone direction, the beater element will be rotated on itsownaxis in the opposite direction, while at the same time its axis is translatedi or revolved around they bowl and around.the.cen.

tral axis of the planetary head.

Shaft 36 (Fig. 3) controls the rotation of the mixer head 22 and carriesfa gear 32 driven by. a

worm;34 on one endofV a connecting shaft 36.` The, other end of shaft 36 carries a gear 38 which is. driven, in turn, by a worm 40 of the motor shaft 42. The gears and worms are shownonly infschematic outline since they form no part.` ofvk the present invention, and since any otherf' suitable driving connections may be employed.

Themotor shaft alSohasa governor or speed control device of. any desired type. .Such a device has been illustrated schematically, in the drawings and includes the governor weights 44 which;y

are fastened by resilient arms 46 to a collar 48 rotatable with shaft 42 but` fixed longitudinally thereon. Additional resilient arms 4l also con-Y` neet. the governor weights -44 to anaxial1vs1id-- able collar 50. Thus, upon rotation of shaft 42, the weights 44 will tend to move outwardly and draw the collar 50 downwardly on shaft 42 as the speed increases.

Slidable governor collar 50 controls the position of the resilient contact arm 52 which cooperates with another contact arm 54 to constitute a governor switch. Arms 52 and 54 are mounted on a suitable insulating block 56 and are provided with contacts 58 and 60 respectively. These contacts may be utilized in circuit with the motor to cut a resistance in or out of circuit land control the speed of the motor in known manner. Thus the position of the one contact arm 52 will be determined in accordance with the speed of rotation of the motor shaft 42 and the axial position of the collar 50 in known fashion.

For manual adjustment of the motor speed and for turning the motor on and off, a movable control member 62 is provided. This control member 62 may have various forms, and a control member similar in some respects to that of my above application is shown for purposes of illustration. Member 62 is slidably mounted on a plate 64 extending longitudinally of the casing extension 20 of the mixer. A finger piece 66 is attached to the control member 62 and is accessible at the outside of the casing for manipulationrby the operator. The control member 62 includes a cam face 68 which engages one edge 10 of an angularly positioned strip l2 pivoted at 14 and 76 to supporting brackets at the ends of slide 64. The axis of pivots 'i4 and '56, and the angular orientation of the member 'l2 with respect to the slide 64 provide for pivotal or rotary movement of the member 12 in response to longitudinal movement of the operating member 62 along its slide 64. Thus, as the slide 62 is moved from the position of Fig. 3 toward the far end of the casing (at which the beater drive shaft is located), the strip 72 will be rocked clockwise (as viewed in Fig. 3) so that a shoulder 18 at one end of the strip is moved downwardly. This shoulder 18 carries an adjusting screw 80 having an insulated tip 82 engaging the upper resilient contact arm 54 of the governor switch. A lock nut 34 holds the screw 80 in its adjusted position. Thus the movement of slide 62 toward the beater end of the housing will cause rocking movement of strip i2 and downward movement of the screw 80 so that the contact arm 54 will become more strongly biased downwardly against contact arm 52. Thus the motor will have to reach a higher and higher speed before the ,collar 50 will move contact 52 downwardly far enough to break the circuit once again.

A main control or on and off switch 86 is also mounted in the casing extension 20 and is connected in the circuit with the motor in known manner so that the motor may be energized and deenergized at will. Switch 86 includes cooperating contacts 88 and 90 which are carried by contact arms 92 and 94 respectively. Contact arm 92 is mounted on an insulating support 98, while contact arm 94 (which is insulated from its contact 90 by strips 96 of non-conducting material) is pivoted at |09` to brackets |02 on the switch support. Thus the contact arm 94 is free to pivot on the axis of pivot to engage and disengage the contacts 88 and 90.

A spring |04 engages one of the insulation strips 96 and urges the contact arm 94 downwardly so that the switch is normally closed. The switch arm 94 also includes a projecting arm |06 extending on the opposite side of pivot |00 from the contact 90 and terminating in a lateral extension or projection |08. This projection |08 is designed for engagement with the cam surface ||0 of a block ||2 mounted on the speed control member 62 by means of a bracket ||4. Thus when the control member 62 is retracted fully to the left, as shown in Fig. 1, the cam surface H0 of member ||2 engages the projection |08 of contact arm 94 and rotates the contact arm about its pivot |00 so that the switch is open and contact is separated from contact 88.

Upon movement of the control slide 62 to the right in Fig. 1, the cam surface l0 will promptly move out of engagement with the projection |08 so that the spring |04 can rotate the switch arm 94 to closed position. Thus the motor I3 of the mixer will be energized and will rotate at a speed controlled by the governor mechanism and depending on the relative extent to which control member 62 has been moved to the right in Fig. l. The farther the member is moved to the right the greater will be the downward bias on governor contact arm 54, and therefore the greater will be the speed at which the motor will operate.

Thus, as described above, the speed control member 62 is movable between the off position of Fig. l and a plurality of on positions in which the motor is energized at various speeds at the will of the operator.

According to the present invention a latch member is provided to hold the speed control member 62 in its off position when the mixer casing |4 is tilted to the retracted position of Fig. 4.' In the specific example shown, the cam member H2 of the speed control member 62 has a vertical latching surface IIS at one end. This surface is adapted for engagement with a hook portion ||8 of the latch member |20 pivoted at |22 to a suitable supporting bracket. Latch member |20 includes a portion |24 extending beyond pivot |22 and provided with a slot |26 in which the crosspin |28 is engaged. This crosspin |28 is carried by the bifurcated end |30 of a shaft |32. The shaft in turn is slidably mounted in a bearing portion |34 of movable casing I4. In the position of Fig. l. the shaft extends substantially vertically and its lower end terminates in a head |36. Between this head |36 of shaft |32 and the bearing portion |34 of the casing a spring |38 is mounted to urge the shaft |32 normally downward. This normal downward position of the shaft is shown in Fig. 4 where it will be apparent that the spring |38 normally causes rotation of latch member |20 to a locking position in which surface H8 is in engagement with surface ||6 of member ||2 and thus holds the speed control member 62 in its off position with switch 86 open.

The lower end |36 of shaft 32 is designed for engagement with the stationary portion |40 at the upper edge of the base or pedestal I2. Thus, when the casing I4 is moved to the operative position of Fig. 1, the shaft end |36 engages the base portion |40 and the shaft |32 is urged upwardly with respect to its bearing portion |34 so that latch |20 is pivoted to its releasing position as shown in Fig. l. In this position the latching surface ||8 is moved out of the path of surface ||6 so that the speed control member 62 may be operated to close switch 36 and adjust the speed of operation of the motor through the governor in the manner described.

'Ihe operation of the speed control mechanism and latch will be apparent from the foregoing description. As long as the casing lil is in the operative position of Fig. l, the latch lll will remain in released position and will not affect the operation of speed control member 62. On the other hand, as soon as the casing lll is tilted to its retracted position as shown in Fig. 4, the latch l2@ will move into locking position. In normal operation it is necessary or customary for the operator to move the speed control member 52 to its olf position before the casing is moved from the operative position of Fig. l to the retracted position of Fig. 4. Should the operator forget to do this, it will still be possible for him to move the speed control member 52 to on position after the casing has been tilted. For this purpose the latch member l2@ has a cam or inclined surface MI which can be engaged by the cam surface il@ cf member IIZ to retract latch against the resilience of its spring |38 when the speed control member 62 is moved to its off position. As the cam surfaces lill and H0 pass each other, the spring 138 will then move latch |28 into locked position, provided the casing I@ at that time is in its retracted position.

According to the present invention a speed control mechanism has been provided in which movement of the speed control member from oli to on position cannot take place until the mixer casing is moved from its retracted to its operative position. Thus the risk of starting the mixer while the beater member is out of the bowl and in position to cause damage is substantially eliminated.

Since minor variations and changes in exact details of construction will be apparent to persons skilled in this field, it is intended that this invention shall cover all such changes and modifications as fall within the spirit and scope of the attached claims.

Now, therefore, I claim:

l. In a household food mixer having a base, a casing mounted above the base for movement between operating and retracted positions, a beater shaft in the casing, a motor operatively connected to the shaft, and a manually operable speed control member movable between an off position and one or more on positions, the improvement comprising a latch member movable between a locking position in which the control member is engaged and held in off position and a releasing position in which the control member is free to move to on position, and means moving the latch member to locked position in response to movement of the casing to retracted position.

2. In a household food mixer having a base, a casing mounted above the base for movement between operating and retracted positions, a beater shaft in the casing, a motor operatively connected to the shaft, and a manually operable speed control member movable between an off position and one or more on positions, the improvement comprising a latch member movable between a locking position in which the control member is engaged and held in off position and a releasing position in which the control member is free to move to on position, and means responsive to movement of the casing for moving the latch member to locking position when the casing is moved to retracted position and for moving the latch member to releasing position when the casing is moved to operating position.

3. A household food mixer according to claim 2 in which the latch member and control member have cooperating cam surfaces temporarily moving the latch out of locking position to permit movement of the control member to off position after the casing is retracted.

4. In a household food mixer having a base, a casing mounted above the base for movement between operating and retracted positions, a beater shaft in the casing, a motor operatively connected to the shaft, and a manually operable speed control member movable between an off position and one or more on positions, the improvement comprising a latch member movable between a locking position in which the control member is engaged and held in off position and a releasing position in which the control member is free to move to on position, resilient means normally urging the latch member to locking position, and means on the base engaged solely in response to movement of the casing to operative position for moving the latch tor releasing position.

5. In a household food mixer having a base, a casing mounted above the base for movementbetween operating and retracted positions, a beater shaft in the casing, a motor operatively connected to the shaft, and a manually operable speed control member movable between an off position and one or more on positions, the rimprovement comprising a latch member mounted in the casing for movement between a locking p0- sition in which the control member is held in 01T position and a releasing position in which the control member is free to move to on position, a plunger mounted in the casing and connected to the latch member, a spring normally urging the plunger and latch to locking position, and an abutment on the base engaged by the plunger on movement of the casing to operative position for moving the plunger and latch to releasing position.

6. A household food mixer according to claim 5 in which the latch member and control member have cooperating cam surfaces temporarily moving the latch out of locking position to permit movement of the control member to off position after the casing is retracted.

7. In a household food mixer having a base, a casing mounted on the base for movement between operating and retracted positions, a beater shaft in the casing, a motor operatively connected to the shaft, and a manually operable speed control member mounted in the casing for sliding movement between off and on positions, the improvement comprising a latch member pivoted in the casing for movement between locking and releasing positions, cooperating means on the latch and control members holding the latter in olf position when the former is in locking position, a plunger connected to the latch member and slidably mounted in the casing, and means on the plunger engaging the base and moving the plunger and latch to releasing position when the casing is moved to operating position.

8. A food mixer according to claim '7 in which the plunger is substantially vertical and has resilient means normally urging the plunger and latch to locking position.

WALTER VAN GUILDER.

No references cited. 

